chrisl

Just a 2kx2k camera, and the data are optically encoded.

That road is probably pretty floppy when you're driving it with the kind of energy a point explosion of a truck bomb (or bigass missile, for Steve) would put in. It's going to both ripple longitudinally and have twisting modes. It could walk/bounce itself off to the side a little and then tumble to get the amount of offset that's there. It also looks like the longitudinal beams sit on small pier blocks on top of the big piers, so it would be tipping off those to one side and could have had enough momentum to tumble as much as it did.

It's 3D data compressed to 2D as a physical part of the data acquisition process, so it's already compressed by the time it hits the detector and lossless compression doesn't reduce the size. You can do lossy compression, but then you can't get the 3D data back.

It's got to have a lot of compression to do that - I take a lot of incompressible video data at 2kx2kx8 bit x 15 fps and that uses half of a GigE pipe for one monochrome camera and spinning drives can't generally keep up with sustained recording - we have to use SSDs to avoid losing frames. The video looking along the bridge very well could be higher than 10 fps frame rate - the frame to frame motion is pretty small for the vehicles, and the resolution is pretty chunky.

We've seen part of that, and it has a big hole in it right at the waterline. It looks like it could be in the righthand lane, but it would be good to see from the road surface side.

Yes. The original shows the bottom ~20% of the lines in the frame saturated when the explosion starts. It's entirely possible for the truck to be intact in the first half of the frame scan (and show that way in the frame) while it's turned into very small parts as the last 20% of the frame is read out. The frame rate and shutter speed aren't terrible for a night-video - the motion is pretty smooth and objects aren't rippled from the line scan. It could be as high as 15 fps - we could work it out backward if someone knows the speed limit on the bridge and the road dashed line marking standards. If we call it 10 fps then there's at least ~120 ms (maybe 220 ms?) where the camera is totally saturated in the original video before the fireball diminishes. And it's complicated by aliasing with the frame rate and compression of the phone used to record the video from the computer monitor.

So the whole problem with the Russian debacle is the fault of Philip Morris and RJR.

Plus the pan on the remaining roadway is dented downward adjacent to the center of the explosion - it happened on top of the bridge. That longitudinal steel beam seems to explain the "crease" next to the dent in the remaining roadway about a foot in from the white line - the thin pan was slammed against the stiff beam. I'd still ride a bicycle across the remaining pavement, and drive inside the lane from the crease in a passenger car, but heavy trucks might accelerate the expansion of some hidden damage and make things interesting.

This picture shows what looks like some deformation of the remaining road bridge deck:

Or could be at the beginning/end where it's back on land with ties and ballast.

Or unwitting person driving a truck full of legitimate explosives with an extra little timed/GPS triggered gift inside. How it was triggered it TBD. But probably the truck, and probably with clean paperwork "official Russian explosives" on the paper not "bad nazi ukrainian explosives" with paperwork that says "washing machines and toilet paper"

Not quite. You're correct that you suspend a bomb 3 feet above the roadway and blow it up, the roadway will reflect the 50% of the energy from the bomb that's going downward back upwards. But all that energy goes downward first, and the roadway experiences a reaction force equal to the force reflecting back up. And the roadway then deforms inelastically, turning a bunch of that energy into bent metal, concrete, and shredded end connectors, and a big splash.

It's a single segment of roadway, or maybe a few that were better connected to each other than the next ones out, like a piece of Hot Wheels track, plopped over several piers. I initially had the impression that they had done single segments to span each gap between piers, but it looks like longer segments that span several. When you slam a hard force down in between two piers, bending it downward, it pulls the roadway longitudinally and yanks the road out of the end connectors. It's why it has nice straight separations at the ends with just some rebar sticking out.

This isn't NYC in October 2001. Russia is actively supplying military materiel across the bridge and you could either stick a triggering charge in an existing Russian shipment or forge a bill of lading for the truck that's something like "10 tons 152 mm HE shells. Pleeze deliver to Nazi Ukrainians through Toobz. From Russia with Love" and then it's not only ok that it's full of HE, but it's *supposed* to be full of HE.

There should be extra likes available on days when the major bridges fall.

How do we know they didn't/haven't been trying? A truckload of legitimate Russian explosives may have just been a target of opportunity and they took advantage when they could. There may be someone Ukrainian guys sitting around watching the rail yards waiting for a chance to get a bomb onto a train, too.

Looks like it went down fast in the initial explosion - there's not a second burst of water from a later splash.

I suspect it's consistent with a big bridge segment getting blown straight down into the water.

So regardless of whose explosives it was and who triggered it, Russia has a problem even if the rail line is still usable. If they're going to use the bridge to send military supplies, which by definition kind of includes large quantities of HE, they need to unload and inspect in detail every single train car that goes across to avoid the same thing happening next week on the rail bridge. So that's about it for supplies to the southern front & Kherson. Fall and mud are coming. None of the routes for supplies are secure (land bridge or Kerch bridge). If the Kerch rail bridge isn't usable, supplies probably have to go by truck through the land bridge, which is going to be lots of fun in the mud.

The last frame where the bottom turns white indicates when the explosion happened. It looks like a rolling shutter CMOS sensor (pretty standard for surveillance cams) that reads out one line at a time to make each picture. The readout was ~4/5 of the way down the frame when the explosion happened - the truck and adjacent car were recorded, and then another ~20% of the lines, then the explosion happened and saturated the remaining ~20% of lines of that frame and all the lines of the next, except for wedges along the left side and top that look like they were in shadow from the light (presumably the camera housing or some kind of enclosure).

The truck is still the best candidate. The guardrails in the intact lane are bent out like the explosion came from the opposite road surface - it looks like the truck might have been just before the pier that the road is bent in half over (with segments down on both sides). The rails on the train side of the dropped portion are also bent towards the train. It also looks like there's a scorch circle with a clean spot centered on the truck - maybe the lower part of the truck shaded that from the scorch. Someone with more direct experience with explody things might comment better on that.

With a Bill of Lading that says it's 2 tons of Russian explosives intended for Russian forces? (edit: It might even be an actual Russian shipment of 2 tons of explosives.) And the remotely triggered part is too small to notice on the x-ray.

The train is a pretty short target in time - do Russian trains run as reliably as Swiss? It might be easier if it's not a suicide bomber to know which truck it's going to be in and follow it in a car with a remote (which could just be a call from a phone). A

So Russia hires inspectors trained by the TSA?

Sure does. Looks like it was in the middle of the one span that's farther from us in the pictures that have the tracks on the right, and the near span looks intact because it is, and just got pulled off the pier. In the side views the span the truck was on is probably the one that's going into the water more steeply because it got pushed down in the middle. So was the train dumb luck or somehow planned? And suicide bomb or planted?